The invention relates to a converter for converting an input voltage into an output voltage, having a switch for controlling the converter under control of a binary signal by means of adaptation of the duty cycle of the binary signal so as to obtain a desired value of the output voltage, which converter has at least two conversion modes and which converter in its operation condition is in one of at least two conversion modes, and selection means for the selection of at least one of the at least two conversion modes.
Such a converter is known from United States Patent Specification 5,475,296. Said Specification describes a switched-mode voltage converter which operates in a so-called buck mode or in a so-called boost mode. The known converter further has means for comparing the output voltage with the input voltage. The result of said comparison is used for determining whether the converter is to be switched from the buck mode to the boost mode or vice versa. If the input voltage is higher than the output voltage the converter is in the buck mode. If the input voltage is lower than the output voltage the converter is in the boost mode.
A drawback of the known converter is that the method of determining when the converter should change from the buck mode too the boost mode or vice versa is comparatively complex.